Changes to system procedures

These are the changes that have been made to system procedures to support virtually-hashed tables:

sp_addsegment – you cannot create a segment on a device that already has an exclusive segment. If you attempt to do so, you see an error message similar to:
```
A segment with a virtually hashed table exists on device orders_dat.
```
sp_extendsegment – you cannot extend a segment on a device that already has an exclusive segment, and you cannot extend an exclusive segment on a device that has another segment.

For example, if you attempt to extend segment orders_seg on a device orders.dat, which already has an exclusive segment, you see an error message similar to:
```
A segment with a virtually hashed table exists on device orders.dat.
```
If you attempt to extend exclusive segment orders_seg on device orders.dat, which has other segments, you see an error message similar to:
```
You cannot extend a segment with a virtually hashed table on device orders.dat, because this device has other segments.
```
sp_placeobject – you cannot use sp_placeobject on a virtually-hashed table, and you cannot place other objects on an exclusive segment. For example, if you attempt to place a virtually-hashed table named orders on a segment, you see an error message similar to:
```
sp_placeobject is not allowed for orders, as it is a virtually hashed table.
```
If you attempt to place object t on segment myseg, which contains a virtually-hashed table, you see an error message similar to:
```
Segment myseg has a virtually hashed table; therefore, you cannot place an object on this segment.
```
sp_chgattribute – does not allow you to change attributes for virtually-hashed tables. For example, if you attempt to change the attributes for table order_line (a virtually-hashed table) like this:
```
sp_chgattribute 'order_line', 'exp_row_size', 1
```
Adaptive Server issues an error message similar to:
```
sp_chgattribute is not allowed for order_line, as it is a virtually hashed table.
```

sp_help – for virtually-hashed table, reports:

That a table is virtually-hashed with this message:
```
Object is Virtually Hashed
```

The hash_key_factors for the table with a message using this syntax:

column_1:hash_factor_1,
column_2:hash_factor_2..., 
max_hash_key=max_hash_value

For example:

attribute_class         attribute       int_value
char_value                                comments                            
---------------------   ---------------  ------------------------
--------------------------------------    -----------
misc table info         hash key factors                     NULL
id:10.0, id2:1.0, max_hash_key=1000.0           NULL